1. Field of the Invention
The present invention relates, in general, to hybrid power trains for vehicles and, more particularly, to a hybrid power train for vehicles which can transmit power from at least one of an internal combustion engine and an electric motor to a mechanism being driven.
2. Description of Related Art
Generally, a hybrid power train for vehicles is a shaft and gear set that is designed to drive a vehicle by optimally, harmoniously and efficiently utilizing power output from an internal combustion engine and power output from an electric motor. To increase driving efficiencies of vehicles, the hybrid power train is configured to efficiently utilize the complementary qualities of the engine torque characteristics and the motor torque characteristics.
A conventional hybrid power train is designed such that, when a vehicle is started or is being driven at low speeds, the hybrid power train enters an EV (electric vehicle) mode, in which the vehicle is being driven by a motor that has good torque characteristics at low speeds, and when the vehicle is being driven at moderate or high speeds, the hybrid power train enters an engine mode, in which the vehicle is driven by an engine that has relatively higher torque characteristics compared to the motor mode, and when the vehicle is required to be driven by substantially high torque, the hybrid power train enters a hybrid mode, in which the vehicle is driven by both the engine torque and the motor torque.
Further, the hybrid power train for vehicles is required to have a variety of driving modes and to realize a plurality of gear stages in each driving mode using a simple construction by optimally utilizing the engine torque characteristics and the motor torque characteristics.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.